package Testdmo4;

import java.util.Scanner;

/**
 * Created with IntelliJ IDEA.
 * Description: 斐波那契数列
 * User:周次煜
 * Date: 2024-03-15
 * Time：10:52
 */

public class Test3 {
    public static int func(int x) {
        if (x<=2) {
            return 1;
        }
        return func(x-1)+func(x-2);
    }

    public static void main(String[] args) {
        Scanner s=new Scanner(System.in);
        int n=s.nextInt();
        int ret=func(n);
        System.out.println(ret);
    }
}
